Just a quickie ....

[Milpol]

Got my latest results which will post later tomorrow for advice as I’m confused by them ...

In the meantime, for starters, could someone please give me a definitive answer to the equivalent of 25 mcg of T3 to Levothyroxine?

Some conversion charts say 25 mcg T3 is equivalent to 100 mcg Levothyroxine and some say it’s 50 mcg Levothyroxine,

Please can anyone give me a definite answer.

Many thanks x

[SeasideSusie Remembering]

Milpol

I have read that Levo is 3 times equivalent of T3, also that it's 4 times. So I always say 25mcg T3 is the equivalent of 75-100mcg Levo. It's not the equivalent of 50mcg Levo.

[Milpol in reply to SeasideSusie]

Thank you Susie, that seems more like it and for coming to my rescue once again!

Most grateful, as always to you x

[Marz in reply to Milpol]

I have read that T3 can vary - according to the brand - more confusion !

[Milpol in reply to Marz]

Thanks Marz, yes I am totally flummoxed by it all !

My quandary is , if I’m on 75 Levothyroxine and 12.5 T3 now, and need to double T3 ( will post new results tomorrow and they are confusing and I need to figure out how to explain them to you guys )

Should I double T3 and stop Levothyroxine altogether as 25 mcg T3 is equivalent to 75 mcg

Levothyroxine?

😘

[Marz in reply to Milpol]

Wait until there are responses regarding your test results before decding what to do. If FT4 is lowish in range there is no need to reduce if it suits you ...

Just post your results with ranges and mention the current dose you are on

[Milpol in reply to Marz]

Thanks Marz, will do. Will post them tomorrow once I’m able to try to understand them myself!

[Marz in reply to Milpol]

Everyone here to help Meant to say - start a new post so more people see it

[Milpol in reply to Marz]

I know, thank you. You are all simply amazing. I really don’t know what we out here would do if this forum didn’t exist because hardly anyone is getting any help from the medical profession!

Thank you 😘

[helvella Administrator Thyroid UK]

No. Because there is no definitive answer.

Typically it is suggested that one third of T4 gets converted to T3, one third to rT3, and the final third just gets excreted.

Follow that through and you could argue that if you are on 100 micrograms of levothyroxine, that results in 33 micrograms of T3. So a 3:1 ratio.

In answer to your direct question, that would be:

25 micrograms T3 = 75 micrograms T4

But many people choosing some form of T3 medicine are doing so because they have impaired conversion. Say that in their bodies the 100 T4 converts to just 25 T3.

That then looks like a 4:1 ratio.

In order to get 33 T3, you would actually need to take 133 T4.

In answer to your direct question, that would be:

25 micrograms T3 = 100 micrograms T4

The more impaired the conversion, the higher the ratio of T4:T3 it appears to be. (Or the greater the "strength" of the T3.)

All the above is for illustration. Nothing to do with thyroid is anything like simple and I certainly don't pretend to have a massive understanding. But if my explanation makes any sense, you will see that the answer can only come from taking it and seeing what happens.

As an initial estimate, I suggest thinking of T3 as being around three times as potent as T4.

[Milpol in reply to helvella]

Wow 😮 thanks helvella. I will have to try to get my teeth round that one !

So now I have to figure out how much Levothyroxine I need to cut out if I’m going to increase my T3 intake.

Many thanks as always, for the amazing help, advice and support you and your team provide xxx

[Hidden in reply to helvella]

Thanks for the explanation. That makes it make much more sense!